Role of the perirhinal cortex in rats' conditioned taste aversion responsememorization

The role of the perirhinal cortex (PC) in conditioned taste aversion (CTA) learning was investigated in Long-Evans rats. CTA was induced by the intrap eritoneal administration of LiCl 60 min after saccharin-sweetened water dri nking. The PC was reversibly inactivated by the stereotaxic administration of tetrodotoxin (TTX) 60 min before saccharin drinking, immediately after s accharin drinking (Experiment 1), 6 or 24 hr after LiCl administration (Exp eriment 2), and 60 min before CTA retrieval testing (Experiment 3). Only pr e-saccharin drinking PC inactivation disrupted CTA. Thus, PC integrity is n ecessary only during the earliest phases of CTA mnemonic processing, that i s, taste information acquisition and early gustatory memory elaboration. Th e results are discussed in relation to PC connectivity and PC temporal invo lvement in the memorization process of other aversive responses.